If you maintain a stand-alone, external instance of vRealize Orchestrator for vRealize Automation, you must upgrade vRealize Orchestrator when you upgrade vRealize Automation from 7.1, 7.2 to 7.3 or 7.1, 7.2, 7.3 to 7.3.1.

If you use a vRealize Orchestrator appliance cluster with vRealize Automation, you must upgrade the Orchestrator appliance cluster to version 7.3 by upgrading a single instance and joining newly installed 7.3 nodes to the upgraded instance.